DK45s Really rough when starting

[beebe44]

I've had my kioti dk45 with 140 hours for about a year. Put about 40 hours on it myself. Since I first got it it really runs rough the first few seconds after starting. I'm just wondering if that is normal? I've wondered since I got it. Black smoke and loud knock but just for the first few seconds, worse when it is colder. Would you say that is normal or indicative of some kind of problem? WIll it get better as it is more broken in? I have been around some other small tractors with a lot more hours and they aren't nearly as rough when I first start them cold. We have a large john deere 200 horsepower tractor and it does the same thing when it is cold but that thing has 8,000 hours and I'm thinking the engine is on it's last legs before a rebuild. All our other large and smaller tractors seem to start pretty smooth even when cold.

 

[k0ua]

Hum... cold it be the glow plugs are not working properly? could you take a voltage reading on the glow plug rail while someone else goes thru the cycle and starts the tractor. Also if you want you could ohm out each glow plug separately after you remove the rail.

Keep in mind that there are really 2 glow plug cycles. the one you "see" with the lamp on for 8 seconds, which the glow plugs really are energized for 15 seconds, and the one you don't see after the start starter is engaged the glow plugs will stop and then re-energize for 15 seconds after starting if the water temp sensor calls for it. If I remember correctly glow plugs are about .4 ohms cold. The coolant sensor is about .5 ohms measured with the contact on, and the water temp below 60C or open above 60C. Of course the display unit controls the relays. and accepts input from the temp sensor. But first measure voltage on the glow plug rail, and if that looks good, disconnect rail and ohm out each glow plug, and go from there. Of course the problem may not have anything to do with glow plugs, but it is a guess on my part. Another thing I believe some people have done is use one of those thermal temp guns and focused the spot on each glow plug to see if they are heating.

When the key switch is in "ON" position
The 12 V of power is supplied to the display unit
(BN) through the "ON" terminal (No. 6) and the fuse
8 (unit) by the contact in the key switch (PP). If the
preheat condition of the temperature sensor (below
60 °C) is satisfied, 12 V of power is supplied to
the coil terminal (No. 41) of the preheat relay (BJ)
through the preheat output terminal (No. 41) of the
display unit (BN).
12 V of power is supplied to the glow plug (BM)
through the relay switch contact for 15 seconds.
Simultaneously, 12 V is supplied to the preheat indicator
terminal (No. 45) of the instrument panel assembly
(PT) to turn on the indicator for 8 seconds.

- When the key switch is in "ST" position
12 V of power is supplied to the display unit through
the terminal No. 42 of the key switch, and this signal
acts as an indicator of the "start" cycle. This
signal acts as an indicator for the “start” cycle. This
input will shut the preheat cycle down to direct all
battery current to the starter. Once the key switch
returns to the “ON” position, the preheat cycle will
operate again as described in the previous paragraph.
This second cycling of the glow plugs is
known as after heating and cycles for 15 seconds
without illuminating the glow light on the dash.

 

[ritcheyvs]

What James said but likely your glow circuit is working OK but you have one or two weak/inop glow plugs. When my DK45S glow circuit was inop the tractor would not start at all. It's not the most accurate but measuring the resistance (ohms) of each plug (with the buss bar removed) is a good place to start if you have a good meter.

 

[beebe44]

Thanks for the reply. I just checked the glow plugs on another tractor so I should be able to check them on the kioti. The other day randomly I couldn't get the kioti to start on the first try. It ALWAYS starts on the first try even though it starts rough. I just turned it off and tried again and it started normally. Now that I think of it there's been a few times I forgot to wait for the glow plugs and it starts just the same even when it is cold out so that might tell me the glow plugs aren't all working. I'll let you know what I find. If it's not the glow plugs I guess I'll just live with it until it gets worse or I can think of what else it might be.

 

[BTI]

If the glow plugs aren't working at all it won't start unless it is VERY warm outside.

BTI

 

[MotorSeven]

BeeBe are you only cycling them once with the ignition key? When it's below freezing here I cycle them 3 times before trying to start and that make a huge difference...no smoke no clatter.

I realize this might mean mine are not all working properly but i have been to lazy to take a look at them.

koua thanks for the detailed test info, now I have no excuse

 

[k0ua]

If there is one thing I can say for the Kioti, is how easy this thing starts, I have owned 5 diesel tractors, and by far this is the easiest starting tractor I have ever owned. One bump of the starter is all it ever takes hot or cold. My Kubota's started OK. the L3400 was a bit rough when cold. it smoked and stammered some when it was really cold out, but this automatic glow plug cycle, and afterheat cycle really works well (when it is working), hope it keeps working on mine! The worst was my old Long 2360, it was challenging when cold.

James K0UA

 

[ritcheyvs]

If the glow plugs aren't working at all it won't start unless it is VERY warm outside.
BTI

That agrees with my experience. But with the glow plugs working mine usually starts fine even with very short glow time (i.e. glow light still on).

 

[Coyote machine]

If you find any problems related to the glow plugs I'd suggest removing all of them and seeing how carboned up each of them might be, and replace any which do not fall into the resistance range specified for them and clean the rest if they are gunked up with any residue of combustion.
Then put everything back together and try the start cycle and see if there is a difference.
Is it stored outside? Have you changed the fuel filter and any other filters and fluids since you acquired the tractor?
Do you use cut/ winterized fuel in it?

 

[ritcheyvs]

What CS said. Also check for excess carbon inside the glow plug hole. If you have a gun-cleaning kit it probably includes bronze bore brushes that work well for cleaning the plug holes. Too much carbon there insulates the plug causing it to overheat and fail prematurely (in addition to preventing the plug from igniting the fuel). Also, if you have an ammeter in the right range (about 20 amps, I think), a measuring the glow plug current (from a battery) is more reliable than trying to measure that small resistance.